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PROTEIN GLOBULE SPEEDS UP THE HEME PHOTOREDUCTION
Author(s) -
Marinov Beniamin S.,
Gerasimenko Vladimir V.
Publication year - 1985
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1985.tb03475.x
Subject(s) - myoglobin , heme , chemistry , flash photolysis , hemeprotein , globular protein , molten globule , photochemistry , electron transfer , photodissociation , cytochrome , cytochrome c , azurin , molecule , electron transport chain , reaction rate constant , protein structure , crystallography , kinetics , biochemistry , organic chemistry , enzyme , mitochondrion , physics , quantum mechanics
— To answer the question whether the external electron can be transferred through the protein globule, the rate of photoreduction of the free heme with dye radicals was compared with that of the heme in various protein environments, in cytochrome c, myoglobin and in heme‐HSA complex. In all cases the globular part of proteins did not prevent the photoreduction of the heme; in fact, it speeded up the process. As determined by flash‐photolysis, the rate constants(1–5) x 10 8 M ‐1 s ‐1 are close to that of the diffusion controlled reactions between molecules of similar size. The experimental data confirm the hypothesis that the native protein globule can transfer external unpaired electrons rather effectively. We make the supposition that this ability is a general feature of proteins but not a function related to electron carriers only.